Quality Bath Did you see the Flory de Colt Drop-in Bathtub by Alcove? http://www.qualitybath.com/product~name~Alcove+Flory+de+Colt+7760AJ~ID~78703.htm

Gina Johnson This is something you might find with the Laufen LB3 series. However as you are seeking something less modern, I would suggest the FORM series which is rectangular but has rounded off corners:

Statements Tile You can get a similar look with a small glass tile such as Vetro Bianco Lux...
http://www.statementstile.com/pages/product.asp?mg={674194BD-4D7D-466C-AFD0-1BAB240F8B26}